The purpose of this study is to determine the myoelectric and motor activity of the human colon in normals and in patients with specific disorders of colonic function. A newly-designed bipolar clip electrode will be used to record colonic slow wave and spike potential activity under basal conditions and in response to feeding and neurohumoral stimuli. Intraluminal pressure as measured with infused open-tipped catheters will be correlated with both parameters of myoelectric activity in subjects and in patients. Differences in slow wave recordable activity, slow wave frequency, spike potential activity, motility index and contractions per unit time will be compared in all groups. Colonic myoelectric and motor activity will be recorded in response to neural agents and the gastrointestinal hormones. Dose-response curves will be constructed to each agent in all groups. Initial studies will be done in normals and in patients with the irritable bowel syndrome. Patterns of myoelectric activity will be correlated with abdominal symptoms, disease activity and response to therapeutic agents. Later studies will extend to colonic diverticular disease, inflammatory bowel disease, intestinal pseudo-obstruction and scleroderma. These studies will apply a sensitive measure of colonic muscle function to the human colon in health and in disease.